After claiming the chairmanship of the Morris County Republican Committee Tuesday night, Ronald DeFilippis and a happy band of core supporters quickly repaired to the hotel bar at the Parsippany Sheraton.

Here they drank, congratulated each other and posed for photos.

Asked about his top priority, DeFilippis quickly answered – making sure Republicans win in congressional districts 7 and 11. That would be incumbent Leonard Lance in the 7th and Jay Webber in the 11th. Most of Morris is in the 11th District, but its western section, which includes DeFilippis’ hometown of Roxbury, is in the 7th. Both races figure to be close. Webber was on hand for the GOP convention, as was Jim Hilk, Lance’s campaign manager.

Nor is the new chairman forgetting about the small details. He also said he would work to defeat Democrat Daniel Kline, who surprisingly won a seat on the Roxbury Township Council  two years ago. Kline, who is up for reelection in 2019, should consider himself warned – the new county GOP chair is gunning for him.

Some of DeFilippis’ key backers were longstanding county Republicans like Guy Gregg and Dick Kamin. Both are former state Assembly members from western Morris.

In looking ahead, they first looked to the past.

Kamin, a onetime GOP chair himself, recalled a bit wistfully how Republican presidential and gubernatorial candidates would carry Morris County by staggering margins – about 80,000 for Ronald Reagan one year and 100,000 for Tom Kean another year.

Things have changed.

Republican candidates still win, but the margins are considerably smaller. Kim Guadagno won the county by an estimated 12,000 votes in last year’s gubernatorial race. Donald Trump won it by about 11,000 in the 2016 presidential race.

Gregg said that Republican dominance in Morris has been eroding ever so slowly over the last decade or so.

One of the alarming facts repeated often during the chairman’s campaign was that Republicans lost 23 municipal seats in the last election.

Both DeFilippis and the man he beat by four votes, Robert Zwigard, pledged to turn things around, or rather, restore order. The mantra throughout the campaign was that Republicans can no longer assume their primary winners are guaranteed victory in November.

But here’s the question.

Why are Democrats becoming more competitive in Morris? Is it really because Republicans are faltering? It is true that success breeds complacency as the cliche goes.

However, that may not be all of it.

The county is changing. The population increase – it jumped from 470,000 to 492,000 from 2000 to 2010  according to Census data – has not been staggering.

But raw numbers may not tell the whole story.

People die; others, generally older people, move away.

New, generally younger people, move in.

Those born at about the time Reagan and Kean were running up their impressive victory margins would be over 30-years-old today. If they’re still living in Morris County, they may very well have views that are more liberal than their parents.

Then there’s Donald Trump. No assessment of politics today can be complete without looking – even briefly – at Trump’s impact on the electorate.

Many partisan Republicans are prone to make comments like, “Everyone I know loves the president, but the media keeps tearing him down.”

Anecdotal evidence has its place, but it really doesn’t go very far.

The average of all polls shows Trump’s approval ratings to be in the low 40’s. Even in the Rasmussen poll, which has been the most friendly to Trump, the president seldom breaks 50 percent.

While New Jersey polling is not as frequent as national samplings, recent polls show Trump’s approval ratings in the state at below 40 percent.

On the same night DeFilippis won his race, Democrats won a special election for a state Senate seat in Wisconsin. Trump had carried the district by double-digits.

Now, there are probably no direct similarities between New Jersey and Wisconsin, but an anti-Republican trend caused by the president himself can not be ignored.

The new chairman’s goals are very worthwhile – energizing the rank-and-file, making fundraisers fun and using the latest technology to reach voters. But will that be enough in today’s political climate?

Therein lies the challenge for DeFilippis and his newly-elected team of officers.

We can not leave the GOP convention without a quick look at the numbers.

There were 492 committee members who checked in with party officials and who were eligible to vote. But there were only 483 votes cast. DeFilippis won 243 to 239.

So, nine county committee people checked in at around 7 p.m., but for some reason did not bother to vote.

Why?  Seems odd, no?

The math isn’t hard here. With a four-vote spread between DeFilippis and Zwigard, nine additional votes could have made a difference.